A three-year clinical study of the use of nifedipine as an adjunct to cold cardioplegia has been initiated in a blinded randomized manner. The markers of efficacy and safety are: 24 Holter EKG recordings for incidence of arrhythmia, serial hemodynamic studies, radionuclide ventriculograms for right and left ejection fractions and 12 segment wall motion analysis, technicium pyrophosphate scanning for myocardial and serial CK-MB iso-enzyme analyses for evidence of cellular injury. Studies are conducted preoperatively, intraoperatively, immediately postoperative (ICU) and at 1 and 6 weeks postoperative. Data and statistical analyses are performed by computer using MUMPS. The clinical trial has been initiated with good results to date.